IRVINE >> Democratic presidential hopeful Bernie Sanders brought his campaign against a “rigged” economy and political system to a boisterous, nearly full Irvine Meadows Amphitheater on Sunday, expressing optimism that he will win the nomination despite a disadvantage in party delegates.

“The reason this campaign is doing so well is that we’re doing something radical in modern politics,” he said in an hour-long speech at the 16,000-seat venue. “We’re telling the truth.

“It is true that billionaires and super PACs are buying elections. The truth is that if we do not allow the Donald Trumps of the world to divide us up, there is nothing that we cannot accomplish.”

The stage was decked with giant American and California flags. Behind Sanders, several hundred supporters waved blue signs with the message “A Future to Believe In.”

They punctuated his speech with cheers, applause, chants of “Bernie! Bernie!” and, at one point, “Si se puede!” the Spanish version of “Yes, we can!”

“We have a shot to win this thing and we are going to fight to win it,” Sanders said. He pointed to the latest polls, which, he said, show “that in almost every instance we beat Donald Trump by much greater margins than does Secretary (Hillary) Clinton.”

The event was Sanders’ first campaign stop in Orange County. On Tuesday, he will make a second local appearance, at the Anaheim Convention Center in his push toward California’s June 7 primary.

The Anaheim function is expected to run from 10 a.m. to 11:30 a.m. Tickets are required and can be obtained from Sanders’ website. Parking may be limited.

After Anaheim, Sanders will head to Riverside and San Bernardino.

In a wide-ranging speech, the Vermont senator hit familiar themes of free public university tuition and health care, paid family leave for new parents, tighter restrictions on Wall Street, higher taxes on the wealthy, comprehensive immigration reform, a $15 hourly minimum wage and investment in infrastructure.

“Our infrastructure in many parts of this country is crumbling,” he said. “We can put people back to work at good wages by fixing that infrastructure.”

In a pointed reference to his long-time opposition to foreign interventions, he suggested, “Instead of rebuilding the infrastructure of Afghanistan, we are going to build the infrastructure of our cities.”

California’s primary will distribute 475 delegates – the most of any state – on a congressional district basis.

Sanders has won 11 of the past 19 contests, but analysts contend Democratic frontrunner Clinton’s early success in large states makes it all but mathematically impossible for Sanders to prevail.

But in an interview before the Irvine rally, Sanders argued that he can overcome the delegate deficit by performing strongly in the remaining primaries and caucuses, and then going after superdelegates committed to Clinton.

Clinton has 2,293 pledged delegates and superdelegates and needs 90 more to win the nomination, although superdelegates can change their allegiance at any time.

Sanders has 1,533 pledged delegates and superdelegates, according to a New York Times analysis.

“In those states where we’ve won significant victories, we’re doing everything we can to get the superdelegates,” he said. The campaign will also turn its attention to superdelegates in other states, noting that about 400 superdelegates had committed to Clinton before any other candidate entered the race.

“That’s more like an anointing process, not a nomination process,” he said.

At the rally, Sanders noted that “Even in those (states) we have lost, we have won overwhelmingly the votes of young people. The vision that we have – the vision of social justice, economic justice, racial justice, environmental justice – that is going to be the vision of the future of this country.”

He bemoaned the amount of money spent on prisons and complained about the high cost of education, citing the crippling student debt that has plagued so many young people. He called for a change of priorities and said a tax on “Wall Street speculation” could cover the cost of tuition at public universities.

“We should be rewarding people for getting an education, not punishing them,” he said.

The enthusiastic audience at the Irvine rally was diverse: old and young, and people of all ethnicities and races. Some sported tie-dye shirts, a few wore Sanders costumes.

Irvine resident Karine Marois, 24, arrived several hours before the event began, dressed as Sanders with slacks, a blue dress shirt, a gray wig, fake glasses and a blazer.

“He’s showing it’s possible to be an honest politician,” said Marois, who is a food scientist. “If we all come together, we can make a change.”

Aliso Viejo resident Lauretta Brown, 65, walked out of the amphitheater after Sanders’ rally saying, “It was a privilege to see him live.”

She had been a Republican for more than 20 years, she said, campaigning to get GOP candidates on the board of supervisors and other agencies. But she has switched parties, she explained, because “billionaires need to pay their fair share.”

Brown was accompanied by her daughter, Caroline Brown, a graphic designer, who said that Sanders has energized her more than any other candidate in the past.

“I’ve voted in every election,” she added. “But this is another level of engagement.”

“I’m voting for the future of the country,” Tsai said, “not for myself.”

Trevor Davis, 18, of Mission Viejo, who will cast his first presidential vote in the primary, said he planned to attend rallies for both Sanders and Clinton.

“The most important issue to me is political corruption and Wall Street corruption,” he said. “That’s huge.”

Clinton is expected to visit Orange County next week, but her campaign has yet to disclose the place and date.

Before the event began, Sanders’ campaign workers canvassed along the line of those waiting to enter the amphitheater, handing out forms for them to register to vote.

“Independent doesn’t mean what you think in California,” canvassers shouted, a reference to people who have mistakenly registered for the American Independent Party and therefore can vote in neither the Democratic or Republican primaries.

Gabriel Zepeda, 23, of Downey decided to re-register; he’s done with the Republican Party, he said.

Zepeda, who describes himself as “a bit fiscally conservative but totally socially liberal,” said dismantling the “big business” model of universities is his most important issue.

“We’re lagging behind other countries,” he added, “even though we say we’re the most forward-thinking country. (Sanders) isn’t afraid to do things others are.”

Another rally goer who registered as a Democrat was Nathan Morbee, who will turn 18 before the November general election. “I’m excited,” he said, adding that Sanders “speaks to younger people.”

Morbee attended the rally with his parents and 13-year-old sister. The family is from Orange.

His mother, Patsy Morbee, wore a Sanders pin on her shirt, but said she doubts that supporting the senator will matter in the end. “I don’t believe in the system,” she said. “It’s not for the people.”

Her husband, Jordan Morbee, said he still has faith, but worries that “even if Bernie were elected, Congress would shut down everything he tried to do. Republicans and Democrats need to remember they’re still Americans. We’re on the same side.”

While Sanders is campaigning with a fervor belying his long-shot status, party insiders worry that he is threatening Democratic unity and could hurt the party’s chance to beat Trump, the presumptive Republican nominee, in the general election.

Democratic leaders hope to quell some of Sanders’ concerns by agreeing to give his supporters more seats on key convention platform committees, according to a Washington Post report.

But it remains uncertain whether that will mollify the candidate. Sanders supporters continue to complain that the party establishment has manipulated rules to favor Clinton.

Last week, Sanders said the party faced a choice to remain “dependent on big-money campaign contributions and be a party with limited participation and limited energy” or “welcome into the party people who are prepared to fight for real economic and social change.”

He also called on Clinton to debate him in advance of the June 7 primary. Clinton has given no indication that she’ll take him up on the offer.

Chris Haire is the senior reporter for the Press-Telegram. He previously was a general assignment reporter for the Orange County Register, covering everything from spot news to human-interest features. He has been with the Register and Southern California News Group since December 2012. He graduated with honors from the Columbia University School of Journalism, with a master's degree. Chris also has a bachelor's degree in journalism from San Francisco State University and would like, one day, to get a doctorate in history. (He's kind of nerdy.) He also loves Russian literature, including Tolstoy, Dostoevsky, Pushkin and Solzhenitsyn.

Martin Wisckol covers coastal environment and development. Previously, he spent two decades as politics reporter and columnist for the Orange County Register. He’s also held reporting positions in Miami, Jacksonville, Detroit and his hometown of San Diego, with an emphasis on land use and urban planning. He is a lifelong surfer and has spent most of his life on the coast. His work has been honored by the Society of Professional Journalists, the National Headliner Awards, the California Newspaper Publishers Association, the Florida Press Club and the American Planning Association Florida Chapter.